there are many ~12 sec SuperPI times, but the lowest i've seen is around 3.8ghz. the first one was at 4.1ghz.
there also seems to be a bug w. cpu-z as it will read the speed at 2.33 even though its actually running at 3.8, ill try and find a link for you but no guarantees. this was late last night and i never keep my history or w/e